Display-Area Test Pad Switching for Seamless Tiled Displays

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Solution Overview

Problem

Traditional light emitting devices with test elements in peripheral areas reduce the screen-to-body ratio and create a sense of seam in tiled displays, affecting display quality and user experience.

Innovation Solution

The test switch elements are integrated into the display area of the electronic device's substrate, allowing for reduced peripheral space and improved spatial configuration, enabling better display effects and seamless tiling.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If test elements are disposed in the peripheral area of the light emitting device, then the testing function is achieved, but the screen-to-body ratio decreases

Engineering Contradiction:
Improvetesting functionVSAvoidscreen-to-body ratio
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The patent applies dimensionality change by moving the test switch element from the peripheral area (2D plane) to the display area (utilizing the Z-axis/depth dimension through pixel column integration). This allows the test element to occupy vertical space within existing pixel structures rather than consuming horizontal peripheral space, thereby maintaining high screen-to-body ratio while preserving testing functionality.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If test elements are disposed in the peripheral area, then the testing function is achieved, but a sense of seam appears in tiled displays

Engineering Contradiction:
Improvetesting functionVSAvoidseamless appearance
Core Design Contradiction:
ReliabilityVSShape

Solution Approach 1:

By relocating test elements to the display area and integrating them within pixel column structures (utilizing the depth dimension), the patent eliminates peripheral gaps that would create visible seams in tiled displays. The test elements become part of the active display matrix rather than external components, ensuring seamless appearance when multiple devices are tiled together.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

3Area of stationary object

If test switch element is disposed in the display area, then the screen-to-body ratio is improved, but the configuration complexity increases

Engineering Contradiction:
Improvescreen-to-body ratioVSAvoidconfiguration complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent merges the test switch element with the pixel column structure, combining testing functionality with existing display elements. The test switch element shares the pixel column's physical space and electrical connections, integrating multiple functions (display and testing) into a single structural unit, thereby reducing overall configuration complexity despite the innovative placement.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The pixel column structure is designed to serve dual purposes: displaying visual information and housing test switch elements for quality assurance. This multi-functionality approach allows the same structural element to perform both display and testing roles, simplifying the overall device configuration by eliminating the need for separate peripheral testing structures.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Data Source

PatentEP4020439B1Electronic device
Publication Date: 2023.09.06 INNOLUX CORP
  • EP4020439B1 patent drawingFigure 1
  • EP4020439B1 patent drawingFigure 2
  • EP4020439B1 patent drawingFigure 3

AI summary

An electronic device (ED) includes a substrate (SB), an electronic unit (EU), a data line (DL), a control unit (CU), a test pad (TP) and a test switch element (TU). The substrate (SB) includes a first surface (FS) and a second surface (RS). The first surface (FS) includes an active area (DA). The electronic unit (EU), the control unit (CU), and the test switch element (TU) are disposed on the substrate (SB) and located in the active area (DA). The data line (DL) is disposed on the substrate (SB). The control unit (CU) is electrically connected between the electronic unit (EU) and the data line (DL). The test pad (TP) is disposed on the second surface (RS) of the substrate (SB). The test switch element (TU) is electrically connected between the data line (DL) and the test pad (TP).